Process for treating cellulose and products therefrom



Patented F ab. 7, 1933 um'raos'rA'ras PATENT orncs PAUL RAB-REE, OF SWITZERLAND, ASSIGNOB TO HEBEBLEIN & 00., A. G, 01

WA'I'TWIL, SWITZERLAND, A OOBPOBA'IION OF SWITZERLAND rnoonss ron rnnarmo cnn'nunosa aim rraonuc'rs memoir Il'o Drawing. Application fled In! 14, 1929, Serial 170. 868,102, and in Germany J'une 15,

This invention relates to a process for treating cellulose and partlcularly to a process for changing its activity towards dyestuffs and for altering other properties thereof. It also relates to products resulting from such treatment.

Esterification of cellulose and re recipitated cellulose (hydro-cellulose) w1t hlgher fatty acids has been heretofore described. Generally heretofore esterification of cellulose and hydro-cellulose was carried out with acid chlorides in the presence of orgamcbases such as pyridine or quinoline while heating to a greater or less degree whereby highly esterified products soluble in or anic solvents were produced. Of. British atent 201 510 of September 6, 1922; H. Gault and P. Ehrmann (Bl. Soc. Chim. 1923, 1235) P. Karrer and ZorkaZega (Helv. Chim. 853 (1922), 6 822 (1923); Griin and Wittka (Zt. f. angew. Oh. 645 (1921); British Patents 283,181 and 284,298; G. Kita and collaborators (Kunststoiielifl (1926)).

All these experiments and processes-deal with the production of esters from loose cotton, cellulose, cellulose dust, paper, and the like, and result mostly in amorphous products devoid of structure.

It has been found in accordance with the present invention that changes in vegetable yarns. and fabrics of all kinds can be produced while ,-'preserving their fibrous structure by superficial esterification thereof by means of higher fatty acids.

An object of the present invention accordingly is to provide a simple, eflicient process for carrying on such surface esterification and to produce a series of products having their activitv towards substantive dyestuffs effectively altered alone' with alterations in other properties such as their appalmitic, stearic, oleic, and similar acids, as

well as mixtures of such acids. By this rocess one obtains a yarn or fabric which as a wooly soft texture. and which, while possessing an undiminished or hardly altered strength has excellent immunity to substantive dyes and is lhlicult to moisten and repels water- These valuable properties constitute a hitherto unknown novel technical effect.

which was not to be foreseen on the basis of previous knowledge.

The proces of producing such effects comprises acting on a vegetable yarn or fabric which has previously been immersed in aqueand may for example, amount to 0.5 mol. or 2 'mol. or 3 mol. to 1 mol. of C H O In addition to yarns and woven materials,

all other kinds of structures for example knitted goods, embroidery, and the like composed of or including material containing cel-, I

lulose may be enobled in this manner. By the expression material containing cellulose, in. accordance with the usual usage in this art, is included regenerated cellulose or other form of artificial Examples of procedure 1/16 parts by weight of cotton cloth-are immersed for 2 hours in a 20-percent aqueous caustic soda solution, are thereupon pressed free of excess causticsolution, and are introduced into carbon tetrachloride in which there has previously been dissolved 28 parts by weight of the acid chloride mixture obtained by treatment of commercial stearin with thionyl chloride and which-therefore consists principally of the chlorides of palmitic and stearic acids. The cotton-fabric remains for some time, for example 1 hour for 2 hours at C. Thereafter one washes with alcohol and water, and dries.

3. After the alkalizing of the cotton fabric with aqueous caustic soda solution, in conformity with Example 1, it is pressed out and dried. Thereupon it is caused to react with a solution of oleic acid chloride in carbon tetrachloride (1 part of acid chloride to 2' parts of alkalized fabric), for 2 hours at C.

In place of the fatty acids mentioned in the above examples, other fatty acids and mix: tures thereof may be employed such as capric caprylic, and lauric acids, and instead of using the chlorides of these or the acids mentioned in the examples, other halides such as the bromides thereof may be employed.

The products resulting from the above example and in general from carrying out the invention described herein, have a fatty feel and are difficult to moisten with water. The treatments described in Examples 1 to 3 serve to alter their activity toward substantive dyestuffs and to render them relatively immune thereto.

Thus while I have described my improvements in detail and with respect to certain preferred forms, I do not desire to be limited to such details or forms since, as will be noticed by those skilled in the art, after understanding my invention and many changes and modifications may be made and the invention embodied in widely different forms without departing from the spirit and scope thereof in its broader aspects, and I desire to cover all modifications, forms and improvements coming within the scope of any one or more of the appended claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A process of the kind described which comprises treating cotton with a caustic alkali and an agent including a product resulting from the treatment of a higher fatty acid with thionyl-chloride, capable of esterifyingthe surface of said cotton, and maintaining the treatment of cotton by said agent to form a water-repellent product having a soft fatty feel and a woolly texture.

2. A process of the kind described which comprises treating a substance containing cellulose with a caustic-alkali, subjecting the alkali-treated substance to an agent including a higher fatty acid halide capable of esterifying said cellulose and maintaining the treatment of cellulose by said agent under conditions to produce a product having a soft fatty feel, a wooly texture and a repellence to moisture.

3. A process of the kind described which comprises treating cotton with caustic alkali, removing the excess af alkali, and subjecting the alkali-treated cotton to a higher fatty acid halide at a temperature and for a suitable time to produce a water-repellent product having a soft fatty feel and a wooly texture.

4. A process of the kind described which comprises treating cotton with caustic alkali, removing the excess of alkali, and subjectin the alkali-treated cotton to a stearic aci halide in a solvent for about an hour and at approximately 3555 G. to produce a superficial reaction between the cotton and said halide.

5. Cellulose retaining substantially its original fibrous structure, superficially, chemically combined with a higher fatty acid having a substantial immunity to substantive dyes possessing a fatty feel and a wooly texture and having a repellence to moisture.

6. Cotton retaining substantially its original fibrous structure and in the form of yarn or otherwise, superficially chemically combined with a substance containing stearic acid having a substantial immunity to substantive dyes possessing a fatty feel and a wooly texture and having a repellence to moisture.

7. A material containin unitary fibers of uncombined and chemical y combined cellulose, retaining substantially the fibrous structure of the uncombined cellulose, said combined cellulose being made up of an ester of said cellulose and fatty acid selected from a group represented by caprylic, capric, lauric, palmitic, stearic and ole1c acids, said material having its activity toward substantive dyestuffs relatively diminished as compared with the untreated material.

8. A water repellent material containing unitary fibers of uncombined and chemically combined cellulose, retaining substantially the fibrous structure of the uncombined cellulose, there being a relatively small proportion of combined cellulose as compared-to uncombined cellulose, said combined cellulose bein made up of an ester of said cellulose and atty acid selected froma group represented by caprylic, capric, lauric, palmitic, stearic and oleic acids, said material having taining substantially the fibrous structure of the uncombined cellulose,said combined cellulose bein made u of an ester of said cellulose and atty aci selected from a groufa represented by caprylic, capric, lauric, pa mitic, stearic and oleic acids, said material having its activity toward substantive dyestufis relatively diminished as compared with the untreated material.

10. A fabric containing cellulose retaining substantially its original fibrous structure chemically combined with a higher fatty acid and have a repellence to moisture, said fabric having its activity toward substantive dyestuffs relatively diminished as compared with th untreated material.

In testimony whereof I have signed my name to this specification.

PAUL KARRER. 

